This specification relates digital information retrieval.
Content displayed on a web page provided by a publisher can included content authored by the publisher and additional content provided by another entity, such as advertisements provide by an advertisement server. The additional content is provided by content item servers in response to content item requests that are generated during the rendering of the web page by a client device. Often a publisher of a web page may define multiple content item environments, e.g., multiple iFrames, for content items to be displayed within a web page. Typically, the client device generates, for each content item environment, an associated content item request, e.g., an advertisement request, that is transmitted to the content item server. For each request, when the client device receives the content items in response to the request, the client device will render the content items in the respective content item environment for which the request was generated.
A web page having multiple content item environments, however, sends multiple requests for content items to the content server. The multiple requests can result in redundant content items being displayed in the different content item environments, which may, in some situations, degrade the user experience. For example, assume the content items are advertisements, and each request has the same or similar request parameters (e.g., the same publisher identifier and keywords). For each request a different advertisement auction is conducted. While each content item environment may display different advertisements within its own environment, some of the advertisements may also be displayed in one or more of the other content item environments, resulting in the display of duplicate advertisements. Accordingly, a suboptimal collection of advertisements may be served for a web page.
Additionally, in the case of advertisements, the running of multiple auction instances for a single instance of a resource is less efficient than running a single auction instance for the resource.